Fish definitely hear. My quarantine tanks were near the stairs and unfortunately if you went down 'heavy footed' they would jump around.
I always talk to my fish every day so they stay used to my sound and vibration, along with appearance. This makes the association stronger with good food and pleasant things. They respond eagerly when I do so. It also keeps them calmer when I'm working in the fishroom because sometimes I have sudden movements doing maintenance. In turn they give me 'cues' when they want more food or haven't had enough food. They'll come up to the top or move front and center and wait patiently, 'watching' me. Two of my fish dance. My O Brick who races like a crazed crackhead, and my large female BP Patch, who shimmys and does fan dances. Then she turns her eyes 'up' at the surface.